<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
        .small{
            width: 350px;
            height: 350px;
            border: 1px solid #ccc;
            float: left;
            background-clip: padding-box;
            position: relative;
        }
        .big{
            width: 540px;
            height: 540px;
            border:1px solid #ccc;
            float: left;
            margin-left: 10px;
            background-clip: padding-box;
            display: none;
        }

        .small .move{
            position: absolute;
            background: rgba(200,200,50,0.5);
            border: 1px solid #999;
            box-sizing: border-box;
            cursor: move;
            display: none;
        }
    </style>
</head>
<body>
    <div class="small">
        <div class="move"></div>
    </div>
    <div class="big"></div>

    <script src="index.js"></script>
</body>
</html>
